﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace Scada.License
{
	internal class DESEncrypt
	{

		public DESEncrypt()
		{
		}

		#region ========加密======== 

		/// <summary> 
		/// 加密数据 
		/// </summary> 
		/// <param name="Text"></param> 
		/// <param name="sKey"></param> 
		/// <returns></returns> 
		public static string Encrypt(string Text, string sKey)
		{
			DESCryptoServiceProvider des = new DESCryptoServiceProvider();
			byte[] inputByteArray;
			inputByteArray = Encoding.Default.GetBytes(Text);
			des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
			des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
			System.IO.MemoryStream ms = new System.IO.MemoryStream();
			CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
			cs.Write(inputByteArray, 0, inputByteArray.Length);
			cs.FlushFinalBlock();
			StringBuilder ret = new StringBuilder();
			foreach (byte b in ms.ToArray())
			{
				ret.AppendFormat("{0:X2}", b);
			}
			return ret.ToString();
		}

		#endregion

		#region ========解密======== 


		/// <summary> 
		/// 解密数据 
		/// </summary> 
		/// <param name="Text"></param> 
		/// <param name="sKey"></param> 
		/// <returns></returns> 
		public static string Decrypt(string Text, string sKey)
		{
			DESCryptoServiceProvider des = new DESCryptoServiceProvider();
			int len;
			len = Text.Length / 2;
			byte[] inputByteArray = new byte[len];
			int x, i;
			for (x = 0; x < len; x++)
			{
				i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
				inputByteArray[x] = (byte)i;
			}
			des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
			des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
			System.IO.MemoryStream ms = new System.IO.MemoryStream();
			CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
			cs.Write(inputByteArray, 0, inputByteArray.Length);
			cs.FlushFinalBlock();
			return Encoding.Default.GetString(ms.ToArray());
		}

		#endregion



	}
}
